Conventional fireplace grates for supporting wood logs and the like generally take the form of a shallow U-shape viewed from the end. Such grates may be referred to as xe2x80x9cbasket gratesxe2x80x9d and serve the limited purpose of holding logs for combustion in a generally satisfactory manner. They do not, however, provide any assistance or assurance in preventing smoke pouring from the fireplace opening during starting of a fire, they are subject to dangerous situations especially when logs are piled high in a triangular configuration and when a partially burned log rolls forwardly onto a floor or carpet, they are not conducive to ease and convenience in starting fires, they are only nominally efficient in radiating heat forwardly through the fireplace opening, they are limited in automatic self-feeding capability, and they provide little or no control over burn rate or the size of the fire, the latter resulting only from constant attention in adding and/or limiting the number of logs stacked on the grates.
It is the general object of the present invention to provide a vertical stackxe2x80x94vertical draft fireplace grate which maintains a vertical stack of logs of limited width in close proximity to the rear wall of the fireplace, thus providing a narrow controlled column of fire and a corresponding narrow vertical draft pattern immediately adjacent the rear wall of the fireplace.
A further object of the present invention is to provide for a xe2x80x9cquick draftxe2x80x9d and thus completely eliminate smoke exiting from a fireplace opening on starting a fire.
Another object of the invention is to positively prevent logs from rolling forwardly from the grate onto the hearth and floor.
Still another object is to make starting a fire the simplest possible yet highly efficient procedure.
Still another object is to provide for an automatic self-feeding function and eliminate the necessity of constant attention from an occupant of the room in which the fireplace is located.
Still another object of the invention is to provide highly efficient radiation of heat from a fire and its associated bed of embers through the fireplace opening into the room in which the fireplace is located.
Still another object is to provide a grate that is nearly as efficient as that of a wood stove.
In accordance with the invention and in fulfillment of the foregoing objects, a vertical stack -vertical draft fireplace grate comprises a log retaining portion which faces generally forwardly and extends sharply angularly upwardly and forwardly from a rear and lower end location closely adjacent the corner formed by the floor and rear wall of the fireplace. The grate portion does not act alone, but instead, retains and supports logs in cooperation with the generally vertical rear wall of the fireplace and defines therewith a sharp generally V-shaped through opening viewed from the sides of the grate. The retaining portion comprises a plurality of parallel log supporting and retaining members spaced apart horizontally a sufficient distance to allow embers from the logs in the grate to radiate freely therebetween and form a deep, vertically, exposed ember bed build up therewithin as a fire progresses. The total area of forwardly open space between the supporting and retaining members is substantially greater than the total area of the members so as to permit heat generated by burning logs on the grate to radiate freely outwardly through the spaces and forwardly from the grate together with heat radiating forwardly from an ember bed within the lower portion of the grate. The grate is open at the top for the downward introduction of logs thereto, and the configuration at lower end portions of the supporting and retaining members is such that burning logs and embers fall into the grates lower portion and onto the fireplace floor as the fire progresses. A pair of legs extend forwardly with one end portion of each engaging the fireplace floor a substantial distance from the grate and the other end portion secured to the log retaining portion of the grate at a substantial distance above the fireplace floor to maintain stability of the grate with the latter carrying a maximum number of logs.
Further in accordance with the invention, the horizontal front to rear dimension of the grate at its lower end portion should be no greater than the diameter of an average log. More particularly, the horizontal dimension between the rear wall of the fireplace and the retaining portion of the grate is preferably no more than six (6) inches. In accordance with the presently preferred practice the dimension falls in the range of three (3) to five (5) inches, three and one half inches (3xc2xd) being presently preferred. The remaining portion of the grate has a vertical dimension at least twice that of its lower end horizontal dimension and preferably four to five times said dimension to accommodate stacking logs in at least an approximate V-shaped configuration. That is, although logs may not be stacked precisely one on top of the other and may instead be staggered to an extent, they are limited horizontally so as to form an overall cross sectional configuration substantially higher that it is wide. An eighteen (18) inch high grate is preferred. All dimensions quoted are appropriate when considering a fireplace opening of 3xe2x80x2xc3x973xe2x80x2 to 4xe2x80x2xc3x974xe2x80x2.
A further important feature of the grate in accordance with the invention resides in the relationship that a growing ember bed rests on and makes contact with the fireplace floor, thus, allowing the draft to only contact the ember bed straight on horizontally and not from underneath as is common with other grates and irons.
The invention also features a design that incorporates a unique horizontal straight on draft, versus the normal under the fire draft with a basket grate. The straight on draft turns vertically upwardly on entering the stack of logs and fans the vertical portion of the ember bed at the rear portion of the fireplace, thus radiating maximum heat. At the same time most of the oncoming draft oxygen is exhausted in combustion at this point, which in turn slows the draft up the backside of the firebox which in turn reduces and controls the burn rate. As a result, this reduces wood consumption greatly and increases efficiency dramatically.
As will be apparent, the vertical stackxe2x80x94vertical rear draft grate of the present invention provides for substantially vertical forwardly inclined exposure of stacked firewood, several logs at a minimum. In starting a fire, the forwardly inclined or overhanging arrangement of the logs is of considerable assistance. Crumpled newspaper or other starting material may be pressed into position with kindling immediately adjacent thereto in the lower portion of the grate, avoiding the difficulty of forcing newspaper or the like into a narrow space beneath a conventional basket type grate. A rapid and efficient starting operation results. The kindling, or even small logs, ignite quickly with a column of heat rising immediately adjacent the rear wall of the fireplace and into the flue to both heats the wall and creates a xe2x80x9cquick draftxe2x80x9d which effectively provides a smokeless start. Subsequent ignition of logs above the starting materials and kindling tends to occur on the rear surfaces of the forwardmost logs and on the bottom and upwardly about both side surfaces of the rear logs. Smoke, occurring on initial ignition at these locations is shielded by the upper and forwardmost logs and with air flowing rearwardly and horizontally inwardly therebetween, the smoke flows efficiently upwardly as desired and into the flue and little or no smoke issues from the fireplace opening.
As combustion continues, a bed of embers forms in the base of the grate and the adjacent rear fireplace wall in a generally vertical configuration viewed from the sides of the grate. A vertical wall of hot coals is eventually exposed forwardly and maximum heat radiation occurs therefrom through the fireplace opening into an adjacent room. The burning vertical stack of logs above the ember bed of course also radiates maximum heat forwardly as compared with a conventional basket grate where the greatest exposure of both the ember bed and burning logs occurs horizontally while only a narrow area of the ember bed and burning logs enjoys forward exposure so as to create heat radiation into an adjacent room. It is believed that heat radiation into an adjacent room is at least doubled with the vertical stackxe2x80x94vertical rear draft grate of the present invention.
Finally, the grate of the invention provides a self-feeding feature with logs placed atop a stack gradually igniting and descending sequentially until they are transformed to embers in the sub-adjacent ember bed. A stack of large hard wood logs has been found to retain embers through the night and easily restarted 8 hours later without using a match, or the like. Conversely, a much faster burn rate can be provided with small soft wood logs. In this regard, no extra attention is needed and the fire will automatically throttle itself, but at the same time the use of smaller and softer wood will give off more heat per hour.